基于外键关联的一对多单向关联

基于外键关联的单向一对多关联是一种很少见的情况，并不推荐使用。 

<class name="Person"><id name="id" column="personId"><generator class="native"/></id><set name="addresses"><key column="personId" not-null="true"/><one-to-many class="Address"/></set>
</class><class name="Address"><id name="id" column="addressId"><generator class="native"/></id>
</class>

create table Person ( personId bigint not null primary key )
create table Address ( addressId bigint not null primary key, personId bigint not null )

http://lavasoft.blog.51cto.com/62575/39317